Lubricant for a controlled-slip differential

ABSTRACT

An improved method of lubrication of a controlledslip differential comprises using a lubricant comprising a static friction reducing amount of an aliphatic phosphate ester and a hydrocarbon base stock having a kinematic viscosity at 210*F. in the range of 1.5-200.0 c.s. and containing a major amount of a hydrogenated polymer of C3-C12 olefin, such as a &#39;&#39;&#39;&#39;true&#39;&#39;&#39;&#39; isobutylene oligomer or of a blend of at least one C13-C29 naphthene and from 0.1-20 parts by weight, based on said naphthene of at least one member from at least one of the following groups (a), (b), (c) and (d): A. A SYNTHETIC LIQUID C3-C8 olefin homopolymer copolymer, or terpolymer; B. A MEMBER FROM GROUP (A) ABOVE WHICH IS AT LEAST PARTIALLY HYDROGENATED; C. A SEVERELY HYDROREFINED NAPHTHENIC LUBE CONTAINING LESS THAN 1% OF GEL AROMATIC HYDROCARBONS; AND D. A SEVERELY HYDROREFINED PARAFFINIC LUBE CONTAINING LESS THAN 1% OF GEL AROMATIC HYDROCARBONS; AND WHEREIN THE AMOUNT OF SAID BLEND WHICH IS PRESENT IN SAID BASE STOCK IS SUFFICIENT TO PROVIDE A GREATER COEFFICIENT OF TRACTION, MEASURED AT 600 FT./MIN., 200*F., 400,000 p.s.i., than would be provided by substitution of the same amount of ASTM Oil No. 3 for said blend in said base stock. The preferred lubricant also contains an extreme pressure additive (e.g. tricresyl phosphate).

United States Patent [1 Gates et al.

[4 1 Sept. 2, 1975 LUBRICANT FOR A CONTROLLED-SLIP DIFFERENTIAL [73]Assignee: Sun Research and Development Co.,

Philadelphia, Pa.

221 Filed: Jan. 17, 1972 [21] Appl. No.: 218,394

[52] US. Cl 252/32.7 E; 252/46.6; 252/49.8; 252/59; 252/75; 252/78 [51]Int. Cl..... C10m 3/42; ClOm 3/40; ClOm 3/32 [58] Field of Search252/32.7 E, 49.8, 59, 78, 252/46.6, 75; 260/950 OTHER PUBLICATIONSRounds, .lour. Chemical & Engineering Data, Vol. 5, No 4, (1960), pp.499-507.

Primary ExaminerDelbert E. Gantz Assistant Examiner-I. Vaughn Attorney,Agent, or Firm-George L. Church; .1. Edward Hess; Barry A. Bisson [5 7ABSTRACT An improved method of lubrication of a controlledslipdifferential comprises using a lubricant comprising a static frictionreducing amount of an aliphatic phosphate ester and a hydrocarbon basestock having a kinematic viscosity at 210F. in the range of 1.5-200.0c.s. and containing a major amount of a hydrogenated polymer of C Colefin, such as a true isobutylene oligomer or of a blend of at leastone C -C naphthene and from 01-20 parts by weight, based on saidnaphthene of at least one member from at least one of the followinggroups (a), (b), (c) and (d):

a. a synthetic liquid C --C olefin homopolymer copolymer, or terpolymer;

b. a member from group (a) above which is at least partiallyhydrogenated;

c. a severely hydrorefined containing less than 1% hydrocarbons; and

d. a severely hydrorefined paraffinic lube containing less than 1% ofgel aromatic hydrocarbons;

and wherein the amount of said blend which is present in said base stockis sufficient to provide a greater coefficient of traction, measured at600 ft./min., 200F., 400,000 p.s.i., than would be provided bysubstitution of the same amount of ASTM Oil No. 3 for said blend in saidbase stock. The preferred lubricant also contains an extreme pressureadditive (e.g. tricresyl phosphate).

naphthenic lube of gel aromatic 20 Claims, 4 Drawing FiguresPATENTEUSEP'ZIQYS 3.903.001

sum 1 er 4 FIGURE l mIPA m n n n NH] 11V CONTROLLED-SLIP DIFFERENTIALPATENTED SEP 2 suanaum FIGURE2 "ROXANA LVFA" FRICTION vs. SLIDING SPEEDSLIDING SPEED (FT. lMlN.)

LUBRICANT FOR A CONTROLLED-SLIP DIFFERENTIAL CROSS REFERENCE TO RELATEDAPPLICATIONS The present application is related to the following listedUnited States applications,

Serial No. Filing Date Title/Inventor(s) 621,443 3-8-67 SyntheticLubricants from Low (Now Abandoned) Molecular Weight Olefms RICHARD S.STEARNS-IRL N. DULING DAVID S. GATES 679,801 1 1-1-67 Traction DriveTransmission Con- 5 (Now U.S. 3,597,358, taining Adamantane Compounds asissued 8-3-71) Lubricant IRL N. DULING- FREDERICK I. GLAZIER-DAVID S.GATES and ROBERT E. MOORE 679,833 1 1-1-67 Traction Drive TransmissionCon- (Now US. 3,595,796. taining Naphthenes, Branched issued 7-27-71Paraffins, or Blends of Naphthenes and Branched Parafiins as LubricantIRL N. DULING and DAVID S. GATES 679,834 1 1-1-67 Blending BranchedParaffin Fluids (Now US. 3,595.797, for Use in Traction DriveTransissucd 7-27-71) mission IRL N. DULING-DAVID S.

GATES and MARCUS w. HASELTINE 679,851 1 1-1-67 Traction DriveTransmission Con- (Now U.S. 3,598,740, taining Paraffnic Oil asLubriissued 8-10-71 cant IRL N. DULING-DAVID S.

GATES-THOMAS D. NEWINGHAM 784,487 12-17-68 Conversion of AdamantancHydro- (now U.S. 3,646,224, carbons to Monools ROBERT E.

issued 2-29-72) MOORE 794.844 1-24-69 Friction Drivc Fluid IRL N.

(Now U.S. 3,608,385, DULING and FREDERICK P.

issued 9-28-71 GLAZIER 812,516 2-19-69 Catalytic Hydrofinishing of Pet-(Now U.S. 3,619,414, roleum Distillates in the Lubissued 1 1-9-71ricating Oil Boiling Range IVOR W. MILLS-MERRITT C. KIRK, .IR. andALBERT T. OLENZAK 823,138 5-8-69 Reaction for Linking Nuclei of (NowU.S. 3,560,578, Adamantane Hydrocarbons issued 2-2-71) ABRAHAM SCHNEIDER850,717 8-18-69 Hydrorefincd Lube Oil and Pro- (now abandoned) cess ofManufacture IVOR W.

MILLS and GLENN Rv DIMELER 876,993 1 I-14-69 Friction or Tractive DriveFluid (now U.S. 3,645,902, Comprising Adamantanes IRL N.

issued 2-29-72) DULING-FREDERICK P. GLAZIER- DAVID S. GATES and ROBERTE. MOORE 5 877,462 1 1-17-69 Combination of Traction Drive (nowabandoned) and Traction Fluid Comprising Saturated Cyclic Compounds IRLN. DULING and FREDERICK P. GLAZIER 3,256 8-19-69 Friction or TractiveDrive Fluid (now U.S. 3,648,531. IRL N. DULING-FREDERICK Pv issued3-14-72) (now abandoned) (now US. 3,778,487

issued 12-11-73) (now U.S. 3,737,477 issued 6-5-73) (now US. 3,676,521,issued 7-1 l-72) GLAZIER-DAVID S. GATES and ROBERT E. MOORE Process forProducing Polyisobutylene Oil ALFRED E.

HIRSCHLER and GARY L. DRISCOLL DULING and FREDERICK P.

GLAZIER Polyisohutylene Oil Having a High Viscosity Index GARY L.DRISCOLL IRL N. DULING and DAVID S.,

GATES Process of Preparing Synthetic Lubricants from Low MolecularOlefins RICHARD S. STEARNS- IRL N. DULING and DAVID S.

GATES Synthetic Lubricants from Low Molecular Weight Olefins RICHARD S.STEARNS-IRL N DULING -Continued Serial No. Filing Date Title/Inventor(s) (now U.S. 3,646,233 issued 2-29-72) and DAVID S. GATES 80,77910-14-70 Reaction of Normal Paraffins with Adamantane Compounds ROBERTE. MOORE 116,985 2-19-71 Lubricant for Controlled-Slip (now U.S.3,825,495 issued 7-23-74) Differential THOMAS D. NEWINGHAM-ALEXANDER D.RECCHUITE- JOHN Q. GRIFFITH, III-MARCUS W. HASELTINE, .IR.

Combination of Tractive Drive and Traction Fluid Comprising SaturatedCyclic Compounds IRL N. DULING and FREDERICK P. GLAZIER ChemicalReaction Products of Polyisobutylene GARY L. DRISCOLL and MARCUS W.HASELTINE, JR.

137,556 4-26-71 Chemical Reaction Product of Sulfur, Lard Oil andPolyisobutylene ALEXANDER D, RECC- HUITE-GRAY L. DRISCOLL TractionTransmission Containing Lubricant Comprising Gem- Structured PolarCompound MARCUS W. HASELTINE, JR. and GARY L. DRISCOLL LubricantComprising Gem-Structured Organo Compound GARY L. DRISCOLL and MARCUS W.HASELTINEJR.

(now U.S. 3,715,313 issued 2-6-73) (now U.S. 3,793,203 issued 2-19-74)(now U.S. 3,843,537 issued 10-22-74) (abandoned lO-2-72) Combination ofTractive Drive and Traction Fluid Comprising Saturated Cyclic or AcyelicCompounds IRL N. DULING and FREDERICK P. GLAZIER The disclosure of allof the above cited applications is hereby incorporated herein (by thisreference). In particular, these applications disclose blendedlubricants which are useful in the present invention, additives whichcan be useful in such lubricants and processes for making individualcomponents of such blends.

BACKGROUND OF THE INVENTION As has been reported by R. L. Kostelak inLubricalion Vol. 56, No. 4, 1970 (pg. 49 et seq.), the principle ofoperation of the conventional differential in todays American automobileremains the same as the Pecqueur differential, invented in 1827.Although this conventional differential generally performs verysatisfactorily, it has one serious shortcoming; namely,

stalling," which occurs when either rear wheel loses traction. Due tothe kinematics of the conventional differential design, the drivingtorque is divided equally between the two rear wheels and is limited bythe wheel with the least traction. Hence, when one wheel loses traction,the vehicle does not move.

To prevent this shortcoming, engineers have developed many ingeniousideas and mechanisms. Each manufacturer has his own descriptive name forhis particular mechanism; for example, Chevrolet Positraction, ChryslerSure-Grip, and Ford Traction-Lok. Generally, however, a differentialincorporating one of these mechanisms is called a locking or limitedslip or controlled-slip differential.

The limited slip differential (sometimes referred to as LSD") used inthe American passenger car is essentially the same as a conventionaldifferential except for the incorporation of some form of frictionmembers (e.g. clutch plates or friction cones). The Kostelak articledescribes the conventional differential and typical controlled-slipdifferentials.

Another pertinent article is Lubricants for Limited Slip Differentialsby John W. Allen, given at Fuels and Lubricants Meeting, Society ofAutomotive Engineers, Houston, Texas, Nov. l3, 1966.

Another description is found in US. Pat. No. 3,236,771 to H. .l. Matson,issued Feb. 22, 1966. The Matson patent also describes some problemsencountered in lubrication of an LSD.

SUMMARY OF THE INVENTION In a combination of a controlled-slipdifferential and a lubricant therefor, an improvement comprises using alubricant comprising a hydrocarbon base stock having a kinematicviscosity at 210F. in the range of l.5200.0 es. and containing ahydrogenated true oligomer of isobutylene or a blend of at least one C,C naphthene and from 01-20 parts by weight, based on said naphthene, ofat least one member from at least one of the following groups (a), (b),(c) and a. a synthetic liquid C -C olefin homopolymer (such as a trueoligomer of isobutylene), copolymer, or terpolymer;

b. a member from group (a) above which is at least partiallyhydrogenated (preferably, to an iodine number less than 20, morepreferably less than and/or having a 195 UVA less than 2.0);

c. a severely hydrorefmed naphthenic lube contain ing less than 1% ofgel aromatic hydrocarbons; and

d. a severely hydrorefined paraffinic lube containing less than 1% ofgel aromatic hydrocarbons;

and wherein the amount of said blend which is present in said base stockis sufficient to provide a greater coefficient traction, measured at 600ft./min., 200F., 400,000 p.s.i., than would be provided by substitutionof the same amount of ASTM Oil No. 3 for said blend in said base stock.The preferred lubricant has a viscosity in the range of 5-50 c.s. at210F., (typically 10-20 c.s.), has a channel point below 32F. (morepreferred below 10F, typically 0 to F.) and also contains an extremepressure (EP) additive (c.g. tricresyl phosphate, zinc dithiophosphate,etc.) and an additive which lowers the static friction of the lubricant(e.g. a surface-active, organic phosphate ester of a linear aliphatic,ethoxylated alcohol).

Preferably, the C -C naphthene has a glass transition temperature in therange of to -30C. and contains as a structural nucleus, a cyclohexylhydrindan, di(cyclohexyl) alkane, adamantane, spirodecane, spiropentane,perhydrofluorene, perhydrobiphenyl, perhydroterphenyl, decaline,norbornane, perhydroindacene, perhydrohomotetraphthene,perhydroacenaphthene, perhydrophenanthrene, perhydrocrysene,perhydroindane-l-spirocyclohexane, perhydrocarylophyllene, pinane,camphane, perhydrophenylnaphthalene or perhydropyrene.

These blended hydrocarbon base stocks are described in theaforementioned applications of Duling et a1 (e.g. see Ser. No. 33,023,filed Apr. 29, 1970) and in the application of Driscoll et al. The trueoligomers of isobutylene are described in the applications of Driscollet a1).

One important property of an LSD lubricant is the relationship betweenthe static coefficient of friction and the dynamic coefficients offriction at various sliding speeds. Generally, the required coefficientsare for steel on steel; however, other reference materials can be used(e.g. steel on paper) depending on the mechanism to be lubricated.

The preferred methods for obtaining the required friction coefficientsinclude two.

One is the LVFA (or Low Velocity Friction Apparatus) method. The LVFAmethod is described by T. D. Newingham in Publication 774A of theSociety of Automotive Engineering (National Fluids and LubricantsMeeting, Tulsa, Oklahoma, Oct. 303 1, 1963) The second method is the R-Hmethod, which is described by M. L. Haviland et a1, FrictionCharacteristics of Controlled-Slip Differential Lubricants, pp 828-843,S. A. E. Transactions (1967).

Certain of the lubricants of the present invention, as will be furtherdescribed hereinafter, produce unusual and very desirable frictioncurves when measured by either of these methods. These desirable curvescan be described as low static-high dynamic friction. A key component ofthese desirable lubricants is an effective amount of a surface-activeorganic phosphate ester of a linear aliphatic, ethoxylated alcohol, saidamount (e.g. 0.1-10 wt%) being effective to reduce the static frictionwhile not greatly reducing the dynamic friction.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings, FIG. 1is an illustration of a controlled-slip differential and will bereferred to with reference to a test method for comparing the dynamictorque obtained from a given combination of lubricant andcontrolled-slip differential. The test can be useful in comparingvarious lubricants in a given differential.

For example, in a limited slip differential (LSD), the Contact platescan be surfaced with swirl patterns to produce high friction. When theplate has become worn, the friction drops drastically and the LSD failsto perform any better than a conventional differential. With a hightraction-LSD fluid, the friction property is inherent in the fluiditself and is not completely dependent on the patterned contactsurfaces. Thus, the lubricated contacts can have high friction (ortraction) even when badly worn.

With reference to FIG. 1, torque measurements are made by attaching abelt 10 around one of the rear wheels 8 and connecting the belt end to acalibrated spring scale 11. The other rear wheel 1 is then turned byhand to slip the differential. The measurement when slip begins is takenas the break-free torque. A second measurement is determined atapproximately 40 rpm (with the wheel 1 being driven by a motor).

The differential in FIG. 1 consists of a ring gear 4, a differentialpinion 6 and cross shaft, and a right 7 and a left 2 clutch plateattached to the differential case. The wheels are connected to thedifferential pinion by the right 5 and the left 3 side gears. Clutchplates are also attached to the left and right axle shafts. Thedifferential assembly and the lubricant are contained in a housing 9.

F lGS. 2, 3 and 3 illustrate, for a number of lubricants, therelationship between the static coefficient of friction and the dynamiccoefficient of friction at various sliding speeds. The FIGS. 2 and 4data was obtained by the LVFA method; whereas, the FIG. 3 data wasobtained by the R-H method.

EXAMPLE 1 466 g. of a commercial a-methyl styrene polymer, obtained byconventional acid-catalyzed polymerization, is placed in a 1-liter roundbottomed flask, attached to a 1-inch column, and dry-distilled withessentially no reflux or fractionation at a pot temperature of about290C, and a vapor temperature of about 210C. under a vacuum of about 6millimeters of mercury. 373 g. of distillate are obtained and about 73grams of material remain in the bottom of the flask at the end of thedistillation. The commercial a-methyl styrene polymer has a softeningpoint of 210F., a Gardner-Holdt viscosity of J-L, a specific gravity of1.075, a refractive index at 20C. of 1.61 a molecular weight of 685, aniodine number of 0, an acid number of 0, and a saponification number of0.

EXAMPLE I1 300 g. of the distillation product of Example 1 is placed ina 316 stainless steel bomb along with 7.5 grams of Raney nickel catalystand the bomb is pressured to 3,000 p.s.i.g. of 100% hydrogen while heatis applied until the temperature in the bomb is 150C. At that point anexothermic reaction occurs and heating is discontinued. The temperatureis allowed to rise to about 230C. and the hydrogen pressure ismaintained at 3,000 psi. for 6 hours at which time the bomb is slowlycooled to ambient temperature while maintaining the hydrogen pressure at3,000 p.s.i. in order to avoid dehydrogenation of the hydrogenatedproduct. The resulting perhydrogenated poly (oz-methyl styrene) oil istopped to remove components boiling below 125C. The remainingperhydrogenated naphthene product has a KV210 of l 1.07 c.s. and aKV100F. of 327.8 c.s. Analysis by nuclear magnetic resonance (NMR) showsthe oil of this example to contain about 40% of trimers (mostlyhydrindan form), and 60% di mers, mainly 1,1,3-trimethyl-3-cyclohexy1hydrindan.

EXAMPLE III A blend of two commercially available polybutene polymers(i.e., 90 vol.% lndapol L-l00 and 10% Oronite Special 6) is completelyhydrogenated to produce a hydrogenated polybutene oil which analyzes 0.5mole percent olefin by the ultraviolet absorbence method. Thehydrogenation is at 200C, 2,000 psi. of 100% hydrogen for 6 hours usingHarshaw Nl0l04P catalyst.

The resulting hydrogenated polyolefin oil has a KV210F. of 13.54 es. anda KVlOO of 162.8.

EXAMPLE IV A blended base oil was compounded from 61.0 volumes of thenaphthene product of Example 11 and 33.1 volumes of the hydrogenatedpolyolefin oil of Example 111. Then 5.9 volumes of a commercial limitedslip axle additive (Lubrizol Company, Anglamol 99LS) was added to theblend to produce a formulated lubricant.

Table 1 describes typical properties of Anglamol 99LS.

TABLE 1 Specific Gravity at 60F., (15.6C.) 1.055 Pounds per Gallon at60F., US. 8.79 Pounds per Gallon at 60F., 1MP. 10.55 Viscosity at 210F.,(989C) SUS 60 Viscosity at 210F., cSt. 10.2

Weight Percent of:

Typical Sulfur 29.2 Phosphorous 2.0

Similarly, other blended base oils (e.g. comprising synthetic paraffinsand naphthenes) and other gear oil additives can be used to formulatesuch lubricants. Other useful additives are those mentioned by F. G.Rounds, Journal of Chem. and Eng. Data, Vol 5, No. 4, October, 1960, pp.504-505. Useful blended base oils and additives are disclosed, forexample, in previously cited applications Ser. Nos. 33,023, and 52,301.

EXAMPLE V Another useful lubricant for a controlled-slip differential,and which is also useful for lubrication of a traction drivetransmission, comprises a blend'of the following (all hydrogenations areto at least 98% saturation):

KV210F. KV100F.

The use in this lubricant of high and low viscosity fractions of thenaphthene and paraffin is an example of dumbelLblending to improveviscosity index.

The Ultraphos 1 1 additive is a surface-active, organic phosphate esterof a linear aliphatic, ethoxylated alcohol, and is further describedhereinafter.

The synthetic sulfurized oil is the invention of Alexander D. Recchuiteand is the subject of application Ser. No. 135,466 (now abandoned). Thisoil can be used as a replacement for sulfurized sperm oil and can bemade by heating sulfur and a blend of from 3095% lard oil and 5% of oneor a mixture of C -C acyclic monoolefin. For example, 10 weight percentof sulfur was added at 250F. to weight percent of a blend 200F., and,finally, blown with air for 1 hour.

Another procedure for making the synthetic sulfurized oil is to heat thelard oil-olefin blend to about 300F., add sulfur (e.g. 5-25%) over a 30minute period (with agitation), then bring the temperature to 335F.,maintain for 2 hours, cool to 200F. and finally blow with air for 16hours. This latter procedure was used for the synthetic sulfurized oilin the above listed lubricant.

The channel point of a lubricant is determined by drawing a channel witha spatula in a sample of lubricant, at a given temperature, and findingthe maximum temperature where the walls of the channel no longercave-in.

EXAMPLE VI A well-worn limited slip differential in a 1965 Buick Skylark(driven over 65,000 miles) was used to compare lubricants, by thepreviously described method.

The used, original fill fluid was replaced with a fresh conventionalpetroleum-based LSD fluid (e.g. solvent refined paraffinic lube plusAnglamol 99LS). Torque measurements were made periodically for the next500 miles. For the last 100 miles, a 6 p.s.i. difference in air pressurein the rear tires caused the differential to slip constantly. It wasbelieved that this tire pressure difference caused the fresh fluid towork into the contact areas. At the end of 500 miles, the conventionalfluid was replaced with the blended traction-LSD fluid of Example lV,which had the same viscosity at 100F. and the same additive system asthe petroleum-LSD fluid. After 40 miles of driving with the 6 p.s.i. airpressure differential in the rear tires the torque measurement at thelow speed dynamic conditions was nearly double that observed when thepetroleum-LSD fluid was used. There was little difference in thebreak-free torque since the static friction is primarily dependent onthe additive system. Table 2 presents the test data obtained from thistesting.

TABLE 2 Torque Through Worn Limited Slip Differential Torque (Lbs)Odome- Break-Free rpm Fluid 80 92 Traction-LSD Fluid charged A graphicrepresentation of the results of this testing can be found in Design andDevelopment of Fluids for Traction and Friction Type Transmissions, byM. W. Haseltine, Jr. 1. N. Duling, P. E. I-Iagstrom, R. J. Stenger andJ. S. Gates, Society of Automotive Engineers Publication 710937 (MeetingOct. 26-29, 1971, St. Louis, M0.)

The high dynamic friction also helped reduce chatter. With high dynamicfriction, static friction can increase to a higher level before chatterwill occur. Thus, low static modifying additives are effective for alonger period of time in a high traction-LSD fluid. This results inlonger LSD fluid life before chatter occurs. In the present invention apreferred low static friction modifier is 01-10% of a surface-activeorganic phosphate ester of a linear, aliphatic ethoxylated alcohol.

EXAMPLE VII Conventional petroleum-LSD lubricant and the blendedTraction-LSD" lubricant of Example IV were compared in four limited slipdifferentials, by the previously described test method. The results ofthese tests are summarized in Table 3. The performance of eachdifferential was improved when lubricated by the blended traction-LSDlubricant.

TABLE 3 Chev. 1969 Petroleum-LSD Traction-LSD Fluid Original TorqueThrough Various Limited Slip Differentials Odometer at Fluid Torque,lhs.

Change Break-Free 40 RPM Odometer at Torque Test Chev. 1969Petroleum-LSD Traction-LSD Pontiac 1970 Petroleum-LSD Traction-LSD FordOriginal Original Original Petroleum-LSD Traction-LSD Any of the usualgear lube additives can be used in the lubricant-differentialcombination of the present invention; however, especially beneficialresults are obtained when 0.25-l% (based on the base stock) Ultraphos ll (or less preferred, Ultraphos 12) is used as one of the additives.Ultraphos 11 is marketed by Witco Chemical Company and has the followingtypical properties:

KV 23.44 c.s. ASTM-Vl 142 KV 2l7.20 c.s. VTF-Vl 132 Melting Point 0C.Glass Transition Temperature 62C. Elemental Analysis Carbon 58.16%Hydrogen 10.47% Oxygen 20.44% Ash 1.58% Phosphorous 5.77% Sulfur 0.4%(Schoniger) Nitrogen 0.l0% Chlorine 10 ppm Alternatively, Antara LB400(General Aniline and Film) can be used instead of Ultraphos as a lowstatic modifier.

Another useful multipurpose additive package which is useful in suchlubricants is 2-15% Anglamol 93, which has been previously described andwhich is a product of Lubrizol Company and comprises a mixture of zincphosphorodithioate and chlorinated hydrocarbons, a typical analysisbeing 3% Zn, 3% P, 16.5% Cl and 16.0% S. A useful extreme pressureadditive can consist essentially of tricresyl phosphate, or a zincdialkyl dithiophosphate, or a mixture thereof.

The present invention involves novel compositions which contain chemicalreaction products which can be produced by the action of sulfur orsulfur monochloride on lard oil and the polyolefins or polyolefin oilsof the aforementioned application-Ser. No. 52,301. Such cosulfurizedcompositions are described in copending application Ser. No. 137,556 andare useful as lubricant additives, particularly in lubricants fortractive drives and limited slip differentials, and are generally usefulas a replacement for sulfurized sperm oil.

A novel substitute for sulfurized sperm oil can be obtained bysulfurizing a blend of 90 to 30 parts by weight of lard oil and 10 to 70parts of an olefin containing 12 to 128 carbon atoms. The sulfurizationis carried out using elemental sulfur. Sulfur monochloride can be usedfor both sulfurizing and chlorinating simultaneously. The sulfurizationinvolves cooking at from 330 to 445F. for 20 minutes to 10 hoursfollowed by blowing with a gas (preferably, at from 125 to 340F. for 30minutes to 20 hours) to remove hydrogen sulfide. With sulfurmonochloride, the preferred cooking temperature is in the range of150-250 (under pressure if desired). The sulfurized oils can containfrom to 25 weight percent sulfur as based on the blend of olefin andlard oil (i.e., 5 to 25 parts by weight of sulfur, per 100 parts byweight of olefin-lard oil blend).

For example, one embodiment of the invention involves using thepreviously described lubricants and from O. ll 0% of a compositionconsisting essentially of a sulfur-containing chemical reaction productof a mixture of lard oil and a true isobutylene oligomer, that is, abranched olefin hydrocarbon having 4N carbon atoms where N is an integerfrom 3-32, said olefin hydrocarbon having the formula:

CH cm I CH-,,+C CH, II z I CH CH, n

wherein n is an integer from O to 29 inclusive, and

wherein Z is:

For example, in tetraisobutylene, for one isomer, n is l and Z is (D);for another, n is 2 and Z is (B); for another n is 2 and Z is (A); foranother, n is l and Z is (C); for another n is l and Z is (E). Fortriisobutylene, for one isomer, n is 0 and Z is (D); for another, n is 0and Z is (C) or (E); for another, n is l and Z is (A); and for another nis l and Z is (B).

The sulfurized product can be produced by blending from 90 to 30 partsof lard oil and from 10 to parts of polyisobutylene, sulfurizing theblend and then blowing the co-sulfurized blend (or co-reaction product)with a gas to remove hydrogen sulfide. The lard oil and olefin generallyare blended together at from 65F. to 340F. and the sulfur added whilethe blend is within this temperature range. In general, the preferredprocess conditions are those taught in application Ser. No.

- -l35,466 of Recchuite, filed on Apr. 19, 1971.

The preferred commercial lard oil generally is described as winter gradelard oil. The principal difference between the less preferred gradessuch as No. l lard oil and the preferred grade is in the greater amountof saturated free fatty acids present in the less preferred grades,which can reduce the solubility of the product. The polyisobutylene,suitable for use in the present invention, can contain from 12 to 40carbon atoms, preferably from 12 to 24 carbon atoms, more preferred 16or 20. The amount of sulfur generally varies from about 5 to 25 percentby weight as based on the blend of lard oil and polyisobutylene. Aninactive sulfurized product is generally desired; therefore, thepreferred oils can contain from 6 to l 1 percent as based on said blend.Under the reaction conditions specified herein, this amount of sulfurwill become chemically bonded in an inactive form. The resultant productcontaining 6 to 1 1 percent sulfur, as based on the blend of lard oiland polyisobutylene, is useful as a friction modifier for manyapplications as well as a cutting oil The amount of sulfur in a givensample of oil is readily determined by X-ray fluorescence. After theamount of total sulfur is determined 100 g. of the oil sample and 20 gof copper powder are placed in a tall 250 ml. beaker setup on a hotplate and equipped with a thermometer and an Unger stirrer operated at1,750 rpm. The sample is heated to 350F. within a 5 minute period andmaintained at 350i 5F. for 1 hour after which it is cooled and filteredthrough filter paper to remove the copper powder. The sulfur content ofthe sample is again determined by X-ray fluorescence which is theinactive sulfur. The loss of sulfur (total minus inactive sulfur) is theamount of active sulfur in the original. The amount of active sulfur inthe sulfurized oil being used as a friction modifier should be less thanabout 2.5%. Generally the preferred friction modifiers which contain 6-11% total sulfur will also contain from 1 to 2% active sulfur.

After cooking the sulfurized oil is blown with a gas to remove H 5. Anygas may be used which dissolves (or otherwise removes) H 8 and does notsignificantly react with the sulfurized oil. Suitable gases include air,nitrogen. carbon dioxide and gaseous perhalogenated hydrocarbons. Air ispreferred for obvious economic considerations. The blowing is mostsimply carried out by bubbling the gas through the sulfurized oil.Alternatively the oil may be sprayed into the gas or a falling curtainof the oil in the gas may be used. Generally the blowing is carried outat from 125 to 340F. 1n the-case of the sulfurized oils containingminimal active sulfur the blowing should not be carried out above about250F. when air is the gas. When a high sulfur content (16-30%) oil isbeing made it is preferred to use gas blowing temperatures above 190F.as this minimizes the active sulfur lost in processing.

The sulfur may be added either as elemental sulfur or sulfurmonochloride (S Cl The elemental sulfur is usually preferred for the lowsulfur (6-1 1%) oils but S Cl is often preferred for the cutting oilapplications because the chlorine also reacts with the oil and serves toimprove the antiweld characteristics of the product.

The sulfurized oils described above are useful as friction modifiers influids of the present invention to reduce the static friction more thanthe dynamic friction. Generally, in such fluids the sulfurized oils areused at from 0.5 to typically 15%, of the overall fluid.

EXAMPLE VIII A three necked, l liter, round-bottomed flask was equippedwith a mechanical stirrer, a gas inlet tube (which also serves forintermittent product removal),

stopped and the layers permitted to separate. The top oil layer (170ml.) was removed and the nitromethane (bottom) layer was returned to thereactor with 5 m1. (3% of product volume) fresh nitromethane added tocompensate for solubility losses. After four twentyminute runs, thereaction was stopped. The catalyst in the nitromethane layer was readilykilled with water with some production of l-lCl fumes. No difficultywith an exotherm was encountered when killing the catalyst. The combinedoil layers (665 ml. including 20 ml. nitromethane) were washed withwater, with 5% sodium hydroxide solution, and twice more with water. Asolvent such as pentane or hexane can be added to facilitate handling.

Although the oil of this example contains all of the novelpolyisobutylene oligimers in the series C, C ..C fractional vacuumdistillation can be used to obtain fractions relatively pure in a givenoligimer (e.g. C or tetraisobutylene").

1n the reaction of this example, small amounts of water in the catalystand/or feed material can act as a reaction promoter. If extremely purematerials are used in the process, a small amount of water can be addedto initiate or hasten the reaction. A lower alcohol (e.g., methanol) oracid (e.g., acetic acid) can also be used as such a promoter. Generally,the reaction rate can be increased (over anhydrous) by addition of 0.ll.5 moles H O per mole of SnCl Polyolefin products, such as that ofthis example, can contain residual tin and chlorine (e.g., 2505,000 ppmCl). These elements, particularly the tin, can be present as ametal-organic compound which imparts EP (extreme pressure lubricant)properties to the product. However, if one desires, the chlorine (e.g.,2,000 ppm) can be removed from the product by heating the product withcalcium oxide (lime) followed by filtration. Mild catalytic hydrogentreatment (e.g. 200 psi. of H ,200C., Harshaw Nl-0l04P catalyst) canalso be used to reduce the tin and chlorine content to very low levels(e.g., Cl from 2,000 ppm. to 6 ppm) and the resulting polyisobutylene(which can be present with hydrogenated polyisobutylene) can be used toproduce the sulfurized product of the present invention.

EXAMPLE IX Polyisobutylene oil, produced as in Example I, wasfractionally distilled, at atmospheric pressure, to obtain a productwhich contained at least weight percent of the C isobutylene oligimer(i.e., tetraisobutylene). The predominantly C fraction boiled in therange of 190245C. and over volume percent boiled at 240C. Analysis byvapor phase chromatography showed that this predominantly C fractioncontained less than 10 weight percent C oligimer and less than 10 weightpercent of the C and higher oligimers.

EXAMPLE X Twenty-two hundred and sixty ml. of winter strained lard oilwere blended with 400 m1. of tetraisobutylene (prepared as in Example 3)in a 5 L kettle equipped with a vibromixer. The mixture was heated to250F. and the vibromixer operated at maximum speed. Sulfur (239 g) wasadded and the temperature of the mixture raised to 375F. for 2 hours.The mixture was then cooled to 200F. and air was bubbled through themixture by means of a glass tube at a moderate rate (below that at whichsplashing and agitation take place) for one hour. The resultingsulfurized oil was analyzed and found to contain 8.23% sulfur. A tengram portion of the sulfurized oil was dissolved in 100 g. of acommercially available solvent refined paraffinic lube having aSimilarly, lubricants can be compounded comprising a syntheticsulfurized oil and/or a surface active, orgame phosphate ester of alinear aliphatic ethoxylated alcohol and various hydrogenated fractionsof true Linear "true" Pulyisobutylenc Oil (Unhydrogenated).

viscosity at 2l0F. of 40.45 SUS, an ASTM viscosity 5 f 1n 0 ls index of104 and containing 12% aromatics (by ASTM polylsoPutylene (or of g f fpolyole 1 D2007). The oil solution remained clear with no sepa- Propemesof some Such true polylsobutylene 011s are ration after being tested at36 F. overnight and for one Summarized below Comparison, P p of P weekat room temperature. troleum lubes are included) in Table 4.

Table 4 COMPARISON OF LPlB* WITH PETROLEUM BASE OILS LPIB l 1.54 4.3740.3 H1.P1B** 118 1.35 3.53 37.7 20.1 75 155 naphthcnic Oil 52 1.39 4.2740.0 36.9 90 225 LPlB 100 2.39 8.78 54.6 235 HLPlB 102 2.47 9.21 56.2139 70 255 naphthcnic Oil 31 2.26 9.53 57 212 70 295 paraffinic lube 982.63 10.28 60 163 0 345 LPlB 98 4.46 24.9 119 305 HLPlB 100 4.20 22.3108 810 75 315 naphthenic oil 0 3.60 22.9 1 10 I730 45 320 hydrogenatednaphthenic oil 7 3.60 22.0 106 1330 -50 325 paraffinic lube 104 4.2722.9 l 10 747 0 385 HLPIB 96 7.17 55.3 256 3,650 50 380 naphthenic oil 25.63 54.9 255 12,500 350 paraffimic lube 103 7.36 55.1 256 3,860 0 450HLPIB 88 11.70 124.1 574 11.810 50 415 naphthenic Oil 0 8.55 128.4 59594.400 10 390 hydrogenated naphthenic oil 0 8.52 l27.0 588 91,000 5 390paraffinic bright stock 97 12.38 l26.l 584 16,300 0 495 ""FullyHydrogenated 1rue" Linear Polyisubutylene (hydrogenation with Ni onKieselguhr, 1000 psi H 400F).

EXAMPLE Xl Winter strained lard oil (2,525 ml.) was blended with 450 mlof 80+% pure triisobutylene (prepared by a distillation similar to thatused in Example 6 but at a lower temperature), in a 5 L kettle equippedwith a vibromixer. The mixture was heated to 250F. and the vibromixeroperated at maximum speed. These conditions were maintained while 266 g.of sulfur were added over a period of minutes. The temperature wasraised to 375F. for 2 hours. The mixture was then cooled to 200F. for 1hour and air was bubbled through the mixture by means of a glass tube ata moderate rate below that at which splashing takes place. The resultingsulfurized oil was analyzed and found to contain 8.5% sulfur as based onthe total composition. A 10 gram portion of the sulfurized oil wasdissolved in 100 g. of the solvent refined paraffinic lube described inexample X. The oil solution remained clear with no separation afterbeing tested at 36F. overnight and for 1 week at room temperature.

EXAMPLE Xll A useful lubricant. for a controlled-slip differential, andwhich is also useful for lubrication of a traction drive transmission,comprises a blend of the following (the hydrogenation was to at least98% saturation):

synthetic sulfurized oil of Example X Made by hydrogenation of a IZ.0cs. (at 2l0F.) distillate fraction of the product of Example VI".

EXAMPLE XIlI Friction data was obtained for a number of oils. Thefriction data was used to plot the curves in FIGS. 2, 3 and 4 hereof.The data for FIGS. 2 and 4 were obtained by the LVFA method (using theapparatus marketed by Roxana Machine Works, St. Louis, Missouri). Thedata for FIG. 3 was obtained by the R-H Friction method, using theGeneral Motors Corporation apparatus.

The following Table identifies the oils of FIGS. 2, 3 and 4:

Oil No.

The blended hydrocarbon portion of Oil 4 Oil 1 plus 1 vol 7: Ultraphosll Oil 1 plus additives Oil 3 plus 1 vol. 7(- Ultraphos ll CommercialPetroleum base LSD fluid (Texaco TL3450) Hydrogenated truepolyisobutylene Oil 6 plus l vol. 7: Ultraphos l l Oil 6 plus 5 vol. 7:Ultraphos ll *The additives are those of the lubricant of Example V.excepting the Ultraphos l l.

"Oil 4 is the lubricant of Example V The curve for Oil 1 in FIG. 2 showsthat the blended hydrocarbon base oil used in the lubricant of Example Vhad a higher static friction than the dynamic friction at sliding speedsin the range of about -120 feet per minute. The blended base oil ofExample V was a blend of naphthenes (i.e., hydrogenated a-methyl styreneoligomers) and hydrogenated polyolefins (i.e., polybutenes).

The curve for Oil 2 in FIG. 2 shows that the Ultraphos 1 l (a surfaceactive phosphate ester of a linear aliphatic ethoxylated alcohol)produced a lowered static friction in the blended naphthene-hydrogenatedpolyolefin hydrocarbon base oil, without greatly altering the averagedynamic friction.

Similarly, the curves for Oils 3 and 4 establish that the otheradditives in the lubricant of Example V did not appreciably lower thestatic friction but that the phosphate ester additive (Ultraphos 11)produced the low static friction in the lubricant.

The friction curve for Oil 5 of FIG. 2 is that of a conventionalcommercial prior art lubricant (containing a petroleum base oil) for alimited slip differential. The curve for Oil 5 shows that this prior artlubricant has a much higher static friction than the average dynamicfriction in the 20-120 feet per minute range of sliding speed.

The curves of FIG. 3 show that similarly shaped curves, to those of FIG.2, are obtained by the R-I-l method.

The curves of FIG. 4 show that the phosphate ester additive can be usedto lower the static friction, without greatly altering the dynamicfriction in hydrogenated polyolefin oils, particularly oils consistingessentially of hydrogenated true polyisobutylene. The hydrogenatedpolyisobutylene used in Oils 6, 7 and 8 had a viscosity at 210F of 33.5c.s. (158 SUS) and at 100F. of 742 c.s. (3,440 SUS).

The curves for Oils 7 and 8 of FIG. 4, indicate that a lubricantcontaining a major portion of a hydrogenated polybutene oil (especiallya true polyisobutylene) and the phosphate ester in amount effective tolower the static friction can be useful as a lubricant for a limitedslip differential. Other, conventional lube oil additives, e.g.,antiwear, dispersant, antirust, antifoam, extreme pressure (EP), andoxidation inhibitors, can also be added to such a lubricant.

Other uses for a lubricant containing the phosphate ester and thehydrogenated polybutylene oil are in wet clutches (such as are marketedby Borg Warner for heavy duty trucks) and in wet brakes (as those usedin tractors). For wet clutches and brakes a lower viscosity oil (e.g.,40-500 SUS at 100F.) is generally desirable.

Other useful additives (instead of or with Ultraphos 11) are AntaraLB400 and Ortholeum 162. The lubricants containing the Ortholeum 162have the better heat stability (that is, to maintain low staticfriction) after 100 hours aging at 300F. Ortholeum 162 consistsessentially of dilauryl phosphate and other similar mixed alkyl acidorthophosphates. Other useful phosphate ester additives (to lower staticfriction) are the phosphate esters of ethoxylated aromatic hydroxy compounds and their mixed esters with aliphatic hydroxy compounds. Theesters can be part esters, (which produce an acidic pH in water, (e.g.,pH about 2).

The blended fluids and limited slip differential lubricants referred toherein, especially that of Example IV, can be used to increase tractionbetween two rolling elements. When traction fluid is used to lubricatehigh speed ball bearings for an example, the main shaft bearings in aturbine engine it reduces ball skidding. Ball skidding is one of thefactors limiting shaft speed. Accordingly, such lubricants can be usedfor high speed and highly loaded bearings. They can also be used forlubrication of overrunning clutches. Such lubricants (in the appropriateviscosity range) can also be useful in conventional nontraction typeautomotive transmissions to provide improved lock-up and provide for theuse of fewer clutch plates. Furthermore, a coating, generally paper,asbestos or resin, is used on clutch plates to increase the coefficientof friction between the plates. This plate coating can sometimes beeliminated when using the fluids of the present invention in such atransmission.

During engagement, there is a sliding motion between the cam or rollersand the races in overrunning clutches. Since wear occurs during theengagement period, a lubricant which reduces engagement time will reducewear and extend service life. In one test, engagement was reduced from 1l to two revolutions simply by replacing the conventional petroleum oilgrease with a grease component of a naphthene-paraffin blend similar tothat of Example IV. The traction fluid and its grease show the greatestadvantage in clutches where load is high enough to elastically deformthe rollers or cams.

Unless otherwise specified, all percentages herein are by weight.

An especially useful naphthene component of a blended LSD FLUID (as inExample V) is 4,9-cis-lcyclohexyl-l,3,3-trimethylhydrindane, which canbe prepared in high yield (about by the hydrogenation ofl-phenyl-l,3,3-trimethylindane over a catalyst containing nickel,palladium or rhodium, in which the hydrogen pressure is held in therange of 600 to 1,500 psig, and the temperature is held substantially inthe range of 200C to 225C. This process is the invention of Peter Hoslerand David S. Gates and is claimed in a later filed application, Ser. No.218,338, Jan. 17, 1972.

The invention claimed is:

1. A lubricant composition comprising a phosphate ester or mixture ofesters selected from a surface active organic phosphate ester of alinear aliphatic ethoxylated alcohol or a mixed alkyl acidorthophosphate and a hydrocarbon base stock having a kinematic viscosityat 210F in the range of l.5-200.0 c.s. and comprising a major amount of(A) hydrogenated liquid polymer of C C olefin or of (B) a blend of atleast one C, C naphthene and from 0.1-20 parts by weight, based on saidnaphthene of at least one member from at least one of the followinggroups (a), (b), (c) and (d):

a. a liquid C C olefin homopolymer, copolymer, or

terpolymer;

b. a member from group (a) above which is at least partiallyhydrogenated;

c. a severely hydrorefined naphthenic lube containing less than 1% ofgel aromatic hydrocarbons; and

d. a severely hydrorefined paraffinic lube containing less than 1% ofgel aromatic hydrocarbons; and wherein the amount of said phosphateester or mixture which is present in said composition is effective toreduce the static friction, measured by the low velocity frictionapparatus, of said base stock.

2. The composition of claim 1 and containing in the range of 0. l-l% byweight of said phosphate ester or mixture.

3. The composition of claim 1 wherein said major amount is of a trueoligimer of isobutylene.

4. The composition of claim 1 wherein said hydrogenated polymer ofcomponent (a) and said hydrogenated polymer of component (b) are atleast 80 mole percent saturated.

5. The composition of claim 1 wherein said C C naphthene has a glasstransition temperature in the range of 90 to 30C. and contains, as astructural nucleus, a cyclohexyl hydrindan, di( cyclohexyl) alkane,adamantane, spirodecane, spiropentane, perhydrofluorene,perhydrobiphenyl, perhydroterphenyl, decalin, norbornane,perhydroindacene, perhydrohomotetraphthene, perhydroacenaphthene,perhydrophenanthrene, perhydrocrysene, perhydroindanel-spirocyclohexane,perhydrocarylophyllene, pinane, camphane, perhydrophenylnaphthalene orperhydropyrene. l

6. The composition of claim 1 wherein said lubricant also contains'anextreme pressure additive.

7. The composition of claim 6 wherein said extreme pressure additiveconsists essentially of a compound of phosphorus.

8. The composition of claim 7 wherein said extreme pressure additiveconsists essentially of tricresyl phosphate or a zinc dialkyldithiopho'sphate, or mixtures thereof.

9. The composition of claim 1 wherein said naphthene compriseshydrogenated dimers and trimers of alpha-methyl styrene.

10. The composition of claim 1 wherein said C -C olefin in component (b)is at least one C, olefin.

1 l. The composition of claim 10 wherein said C olefin consistsessentially of isobutylene.

12. The composition of claim 9 wherein said blend contains from 01-20parts by weight, based on said naphthene, of a hydrogenated polymer of aC monoolefin.

13. The composition of claim 1 wherein said kinematic viscosity at210F., is in the range of -50 c.s. and wherein the channel point is atleast 10F.

14. The composition of claim 3 also containing from 0. ll0 wt of asynthetic sulfurized oil consisting essentially of a co-sulfurized blendof 9030 parts of lard oil and 10-70 parts of an aliphatic olefincontaining 12 to 128 carbon atoms.

15. The composition of claim 3 wherein said true oligimer of isobutylenehas 4N carbon atoms where N is an integer from 3-32 and has the formulaCH CH3 where n is an wherein z is:

integer from 0 to 29 inclusive, and

1. A LUBRICANT COMPOSITION A PHOSPHATE ESTER OR MIXTURE OF ESTERSSELECTED FROM A SURFACE ACTIVE ORGANIC PHOSPHATE ESTER OF A LINEARALIPHATIC ETHOXYLATED ALCOHOL OR A MIXED ALKYL ACID OTHOPHOSPHATE AND AHYDROCARBON BASE STOCK HAVING A KINEMATIC VISCOSITY AT 210*F IN THERANGE OF 1.5-200.0 C.S. AND COMPRISING A MAJOR AMOUNT OF (A)HYDROGENATED LIQUID POLYMER OF C3-C12 OLEFIN OR OF (B) A BLEND OF ATLEAST ONE C13-C29 NAPHTHENE AND FROM 0.1-20 PARTS BY WEIGHT, BASED ONSAID NAPHTHENE OF AT LEAST ONE MEMBER FROM AT LEAST ONE OF THE FOLLOWINGGROUPS (A), (B), (C) AND (D): A. A LIQUID C3-C8 OLEFIN HOMOPOLYMER,COPOLYMER, OR TERPOLYMER, B. A MEMBER FROM GROUP (A) ABOVE WHICH IS ATLEAST PARTIALLY HYDROGENATED, C. A SEVERELY HYDROREFINED NAPHTHENIC LUBECONTAINING LESS THAN 1% OF GEL AROMATIC HYDROCARBONS, AND D. A SEVERELYHYDROREFINED PARAFFINIC LUBE CONTAINING LESS THAN 1% OF GEL AROMATICHYDROCARBONS, AND WHEREIN THE AMOUNT OF SAID PHOSPHATE ESTER OR MIXTUREWHICH IS PRESENT IN SAID COMPOSITION IS EFFECTIVE TO REDUCE THE STATICFRACTION, MEASURED BY THE LOW VELOCITY FRICTION APPARATUS, OF SAID BASESTOCK,
 2. The composition of claim 1 and containing in the range of 0.1-10% by weight of said phosphate ester or mixture.
 3. The composition ofclaim 1 wherein said major amount is of a true oligimer of isobutylene.4. The composition of claim 1 wherein said hydrogenated polymer ofcomponent (a) and said hydrogenated polymer of component (b) are atleast 80 mole percent saturated.
 5. The composition of claim 1 whereinsaid C13-C29 naphthene has a glass transition temperature in the rangeof -90* to -30*C. and contains, as a structural nucleus, a cyclohexylhydrindan, di(cyclohexyl) alkane, adamantane, spirodecane, spiropentane,perhydrofluorene, perhydrobiphenyl, perhydroterphenyl, decalin,norbornane, perhydroindacene, perhydrohomotetraphthene,perhydroacenaphthene, perhydrophenanthrene, perhydrocrysene,perhydroindane-1-spirocyclohexane, perhydrocarylophyllene, pinane,camphane, perhydrophenylnaphthalene or perhydropyrene.
 6. Thecomposition of claim 1 wherein said lubricant also contains an extremepressure additive.
 7. The composition of claim 6 wherein said extremepressure additive consists essentially of a compound of phosphorus. 8.THE COMPOSITION OF CLAIM 7 WHEREIN SAID EXTREME PRESSURE ADDITIVECONSISTS ESSENTIALLY OF TRICRESYL PHOSPHATE OR A ZINC DIALKYLDITHOPHOSPHATE, OR MIXTURES THEREOF.
 9. The composition of claim 1wherein said naphthene comprises hydrogenated dimers and trimers ofalpha-methyl styrene.
 10. The composition of claim 1 wherein said C3-C8olefin in component (b) is at least one C4 olefin.
 11. The compositionof claim 10 wherein said C4 olefin consists essentially of isobutylene.12. The composition of claim 9 wherein said blend contains from 0.1- 20parts by weight, based on said naphthene, of a hydrogenated polymer of aC4 monoolefin.
 13. The composition of claim 1 wherein said kinematicviscosity at 210*F., is in the range of 5- 50 c.s. and wherein thechannel point is at least 10*F.
 14. The composition of claim 3 alsocontaining from 0.1- 10 wt % of a synthetic sulfurized oil consistingessentially of a co-sulfurized blend of 90- 30 parts of lard oil and 10-70 parts of an aliphatic olefin containing 12 to 128 carbon atoms. 15.The composition of claim 3 wherein said true oligimer of isobutylene has4N carbon atoms where N is an integer from 3- 32 and has the formula 16.The composition of claim 15 wherein said hydrocarbon base stock consistsessentially of said oligomer of isobutylene.
 17. The composition ofclaim 1 wherein said ester is a part ester which can produce an acidicpH in water.
 18. The composition of claim 1 wherein said ester is of alinear aliphatic ethoxylated alcohol.
 19. The composition of claim 1wherein said ester consists essentially of mixed alkyl acidorthophosphate.
 20. The composition of claim 19 and containing dilaurylphosphate.